Macintosh Family: Batteries and Part Numbers, Part 2

This document provides information and part numbers for backup and system batteries used in portable and desktop Macintosh computers between 1997-11 and 2006-11. For Macintosh computers introduced prior to 1997-11, see, "Macintosh Family: Batteries and Part Numbers".

This article has been archived and is no longer updated by Apple.

Some Macintosh computers have a backup battery to maintain system settings, such as the date and time, when the computer is turned off . The battery may last up to five years. However, this varies due to the battery's shelf life, and usage patterns of the computer. The batteries used in Macintosh computers are lithium or alkaline, and are commonly 3.6 V to 4.5 V.

If your computer does not retain parameter RAM (PRAM) settings when it is turned off, this generally indicates that the battery needs to be changed. Some Macintosh models may display a black screen when you turn them on if the battery needs to be changed.